This is another in the long list of Dirk Pitt novels. The story itself is interesting and fast-moving. Historical details of previous arctic explorations are added at appropriate times and give an authentic tone to the story. Nevertheless, some of it is just not credible. The assassin Clay Zac is inept for a professional killer. He bumbles the attempted killing of Lisa Lane, Dirk Pitt (a couple of times), and the crews of the Polar Dawn and the Narwhal. He should learn a trade and get a different job. Making a good man (Trevor Miller) into a killer is also not believable. Nothing in his character explains his revenge for his brother's death. The premise of artifical photosynthesis as a means of saving the planet is known, but the process is not perfected. I think the main problem of the ending is the authors' attempts to tie up all the loose ends and have everyone live "happily ever after".